(1) Field of the Invention
This invention relates, broadly speaking, to a safety device for vehicles.
More particularly, this invention relates to an improved air bag device for a vehicle, the high-pressure fluid reservoir of which device is mounted completely within the steering column of the vehicle.
(2) Description of the Prior Art
Air bag devices for vehicles are known and generally comprise a reservoir for holding highly pressurized fluid, or in which highly pressurized fluid is generated as hot products of combustion resulting from the ignition of rapidly combustible material, or a combination of both sources of pressurized fluid. The reservoir has an exit provided with a seal of one sort or another which prevents the escape of pressurized fluid into an air bag which is coupled, directly or indirectly, to the reservoir. In the event of a collision, the seal is opened, and pressurized fluid escapes from the reservoir into the air bag to inflate it.
An air bag requires a certain number of cubic feet of fluid for proper effective inflation.
A typical air bag for placement on the driver's side of the vehicle has an inflated volume of 1.6-2.3 cubic feet. For a 2.3 cubic foot air bag which is to be inflated, for example, solely by fluid which is stored in a reservoir under pressure prior to a collision and not by or with the aid of hot products of combustion resulting from the ignition of rapidly combustible material such as ARCITE. If the volume of the reservoir is 50 cubic inches, the pressure of the fluid in the reservoir prior to deployment of the air bag will be approximately 1700 psi for proper effective inflation of the air bag. For this same air bag, under the same operating conditions, if the volume of the reservoir is 28 cubic inches, the pressure of the fluid in the reservoir prior to deployment of the air bag will be approximately 3000 psi for proper effective inflation of the air bag.
Smaller reservoirs are generally desirable so that they may be fitted into smaller and more conveniently situated locations in the vehicle. The smaller the reservoir supplying pressurized fluid, the higher must be the pressure of the fluid in the reservoir to properly and effectively inflate the air bag in the event of a collision.
Notable improvements in air bag devices are disclosed in U.S. Pat. No. 5,152,550 (1992) in the names of Larry D. Hoagland and Stephen J. Brockman, in U.S. patent application Ser. No. 07/940,981 filed in the names of Stephen J. Brockman, Larry D. Hoagland and Michael F. Fink, in U.S. patent application Ser. No. 07/964,395 filed in the names of Stephen J. Brockman and Michael F. Fink, and in U.S. patent application Ser. No. 07/987,362 filed in the names of Stephen J. Brockman, Michael F. Fink and Larry D. Hoagland, all assigned to the assignee of the present invention. The aforesaid patent and patent applications, while meritorious in themselves, neither disclose nor suggest the unique combination of the high-pressure fluid reservoir of the air bag device with the steering column of the vehicle disclosed herein.